Modern manufacturing operations and other operating devices use many types of equipment that are subjected to loads that cause heating in portions of the particular machine or unit. Sometimes the heating occurs in electrically powered equipment, such as electric motors, welding transformers, and welding guns. The heating may also occur in equipment such as gear boxes, bearings, and machining equipment that experience frictional loading. Often the equipment is used in circumstances that make maximum use of its design capabilities and may result in substantial heat generation within a particular heavily loaded, manufacturing unit. Further, the equipment may be expected to operate with minimal operator attention or oversight.
In many cases the equipment may be shrouded by shields, casings, or guards which render visual monitoring difficult, or the equipment may be located where physical and/or visual access is limited.
Thus, there is a need for inexpensive and low energy-consuming devices that may be adapted to function autonomously as temperature monitors, providing a remote, machine-specific, overheat signal or over-temperature signal. There is a need for such devices to fit, non-obtrusively, on the equipment, or in thermal communication with the equipment, or within the equipment. Such devices should trigger a warning signal, preferably in a central or well-trafficked location, if, or when, some portion of the equipment reaches a temperature that is likely to be harmful to its continued operation and indicates an overheating condition.